UNI-T UT305A, User Manual, Page: 20 / 26

20
Note
It works best to compare two similar motors operating
similar loads.
1. Press SET and then press / to select relatively
high emissivity.
2. Press
YELLOW button to select MAX.
3. Enable motor and allow it to reach steady state
operating temperatures.
4. Disable the motor if possible.
5. Measure the two motor bearing temperatures
6. Compare the two motor bearing temperatures.
Unequal temperatures or a high temperature can
indicate a lubrication or other bearing problem that
is resulting from excess friction.
7. Repeat the sequence for the blower bearings.
Testing Belts and Sheaves
1. Press SET and then press / to select relatively
high emissivity.
2. Press
YELLOW button to select MAX.
3. Enable the motor and allow it to reach a steady state
operating temperatures.
4. Aim the Thermometer at the surface to be measured.
5. Start recording temperature
6. Slowly move the Thermometer up the belt toward
second sheave.
l
If belt is slipping, sheave temperature will be high
from friction.
l
If belt is slipping, belt temperature will remain
high between sheaves.
l
If belt is not slipping, belt temperature will reduce
between sheaves.
l
If inner surfaces of sheaves are not a true “V”
shape, this indicates belt slippage and will continue
to operate at elevated temperatures until sheave
is replaced.
l
Sheaves must be properly aligned (include “pitch
& yaw”) for belt and sheaves to operate at appropriate
temperatures. A straight edge or taut string, can
be used to check alignments.
l
Motor sheave should operate at a temperature
consistent with blower sheaves.
l
If motor sheave is at a higher temperature at motor
shaft than at outer circumference, belt is probably
not slipping.